JP2001179975A - Piezoelectric/electrostriction actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric/electrostriction actuator having good productivity and capable of readily and stably achieving a sealing property to the other member at a bonding face. SOLUTION: In a piezoelectric/electrostriction actuator 45, a part of a wall section of a pressurizing chamber formed in a base body can be deformed by a piezoelectric/electrostriction element. A spacer plate 70 having at least one window section 76, a closing plate 66 and a connection plate 68 having a first communication opening section 72 provided to a portion corresponding to the window section are laminated by a green sheet and are integrally baked to form a ceramic base body 44, thereby forming the base body. The piezoelectric/electrostriction element 78 is constituted of a piezoelectric/ electrostriction operating section consisting of electrodes 75, 77 formed on the outer face of the closing plate by a film forming method and piezoelectric/ electrostriction layer 79.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric / electrostrictive actuator, and more particularly to a novel structure of a piezoelectric / electrostrictive actuator which has excellent manufacturability, and attains advantageous improvement and stabilization of operation characteristics. Things.

[0002]

2. Description of the Related Art In recent years, as one of mechanisms for increasing the pressure in a pressure chamber formed inside a base of an actuator, the volume of the pressure chamber is reduced by displacement of a piezoelectric / electrostrictive element provided on the wall of the pressure chamber. Known are those that are changed. Such a piezoelectric / electrostrictive actuator is used, for example, as an ink pump of a print head used in an ink jet printer, and supplies a pressure in a pressurized chamber in which ink is supplied and filled, and a piezoelectric / electrostrictive element. The ink droplets (droplets) are ejected from the nozzle holes communicating with the pressurizing chambers, and printing is performed.

[0005] More specifically, FIGS. 5 and 6 show an example of an ink jet print head using a piezoelectric / electrostrictive actuator as an ink pump. In these figures, reference numeral 16 denotes an ink nozzle member, which is formed by a metal nozzle plate 4 having a plurality of nozzle holes 2 and a metal orifice plate 8 having a plurality of orifice holes 6. It is formed by laminating and joining with the passage plate 10 interposed therebetween. Inside the passage plate 12, an ink ejection flow passage 12 that guides ink to the nozzle hole 2 and an ink supply flow passage that guides ink to the orifice hole 6 are formed. A path 14 is formed. Reference numeral 25 denotes a piezoelectric / electrostrictive actuator used as an ink pump. Each of the nozzles of the ink nozzle member 16 is provided in a base 24 formed by laminating plates 18 and 20 made of metal or synthetic resin. A plurality of voids 22 corresponding to the holes 2 and the orifice holes 6
On the outer surface of the closing plate 18, a piezoelectric / electrostrictive element 28 is fixed at a position corresponding to each space 22. Then, the ink nozzle member 16 and the actuator 25 are overlapped and bonded and integrated, so that a pressurizing chamber 26 for pressurizing ink is formed in the space 22.

However, in the actuator 25 used there, small pieces of the piezoelectric / electrostrictive elements 28 must be adhered to the walls of the pressurizing chamber 26 one by one. It is extremely difficult to reduce the size, and furthermore, there is an inherent problem that an increase in cost due to such bonding is unavoidable, and it is difficult to maintain reliability.

In addition, in the actuator 25, the dimension between the cavities 22 and 22 formed adjacent to each other, that is, the thickness dimension of the partition wall 30 between the adjacent cavities 22 and 22:
Since t was as small as about 1 mm or less, it was extremely difficult to adhere to the ink nozzle member 16.

Specifically, when the ink nozzle member 16 and the actuator 25 are bonded to each other, since the adhesive easily protrudes on both sides of the partition wall 30, the protruding adhesive deforms the ink flow path and the pressure chamber. As a result, the ink ejection characteristics are hindered, which leads to a reduction in product quality and a reduction in yield.

If the amount of the applied adhesive is reduced in order to prevent such an adhesive from protruding, a portion where the adhesion is poor is likely to occur.
The seal between the seals 6 and 26 is incomplete, causing pressure to leak, causing crosstalk, and leaving a gap between the bonding surfaces, causing air to remain and resulting in a pressure loss, thereby deteriorating the operating characteristics of the actuator 25. As a result, there is a fear that the problem that the ink ejection characteristics are deteriorated may be caused.

[0008]

The present invention has been made in view of the above circumstances, and has as its solution the problem of bonding with another member (for example, an ink nozzle member of an ink jet print head). Is easy,
The above-mentioned problems due to the protrusion of the adhesive from the bonding surface or incomplete bonding can be reduced or prevented as much as possible, and excellent operating characteristics can be stably obtained, and the manufacturing is easy and compact. An object of the present invention is to provide a piezoelectric / electrostrictive actuator which can be advantageously used.

[0009]

In order to solve the problem, a feature of the present invention is that a part of a wall of a pressurizing chamber formed inside a base is deformed by a piezoelectric / electrostrictive element. In a piezoelectric / electrostrictive actuator adapted to generate a pressure in the pressurizing chamber, a spacer plate provided with at least one window portion, and a blockage which is overlaid on one side of the spacer plate and covers the window portion. A plate and a connection plate, which is overlapped on the other side of the spacer plate and covers the window portion and has an opening at a position corresponding to the window portion, are formed by laminating green sheets, respectively, and are integrally formed. The base body is constituted by the fired ceramic body, and a pressure formed by an electrode and a piezoelectric / electrostrictive layer formed on the outer surface of the closing plate by a film forming method. The / electrostrictive operation portion, the piezoelectric /
That is, an electrostrictive element is formed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to clarify the present invention more specifically, representative embodiments of a piezoelectric / electrostrictive actuator according to the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 and 2 schematically show an example of an ink jet print head using a piezoelectric / electrostrictive actuator according to the present invention, and FIG. 3 is an exploded perspective view thereof. It is shown. The ink jet print head 40 is formed by joining and integrating an ink nozzle member 42 and a piezoelectric / electrostrictive actuator 45, and ink supplied to a pressurizing chamber 46 formed in the actuator 45 is used. The ink is ejected through a nozzle hole 54 provided in the ink nozzle member 42.

More specifically, the ink nozzle member 42
Is a nozzle plate 4 having a thin plate shape.
The orifice plate 8 and the orifice plate 50 are overlapped with a flow path plate 52 interposed therebetween, and are integrally joined by an adhesive.

The nozzle plate 48 has a plurality of (three in this embodiment) nozzle holes 54 for ejecting ink.
The orifice plate 50 and the flow path plate 52 have through holes 56, 57 penetrating in the plate thickness direction at positions corresponding to the nozzle holes 54, and have inner diameters larger than the nozzle holes 54 by a predetermined dimension. It is formed with.

Further, the orifice plate 50 is provided with a plurality (three in this embodiment) of orifice holes 58 for supplying ink, and a window 60 provided in the flow path plate 52 is provided. The nozzle plate 48 and the orifice plate 50 are covered with the nozzle plate 48 and the orifice plate 50 by being covered from both sides.
An ink supply channel 62 communicated with each of the orifice holes 58 is formed between the ink supply channels 62 and 0. The orifice plate 50 is provided with a supply port 64 for supplying ink guided from an ink tank to the ink supply flow path 62.

The material of each of the plates 48, 50, and 52 constituting the ink nozzle member 42 is not particularly limited. However, in forming the nozzle hole 54 and the orifice hole 58 with high dimensional accuracy, Generally, plastics or metals such as nickel and stainless steel are preferably used. Further, the orifice hole 58 is formed, for example, in a tapered shape having a smaller diameter in the ink flowing direction as shown in the drawing, in order to perform an action like a check valve on the supplied ink. It is desirable.

On the other hand, the piezoelectric / electrostrictive actuator 45
Is composed of a ceramic base 44 and a piezoelectric / electrostrictive element 78 formed integrally with the ceramic base 44. Further, the ceramic base 44 is integrally formed with a structure in which a closing plate 66 and a connection plate 68 each having a thin plate shape are stacked with a spacer plate 70 interposed therebetween.

The connection plate 68 has a first communication opening 72 and a second communication opening 72 at positions corresponding to the through holes 56 and the orifice holes 58 formed in the orifice plate 50 of the ink nozzle member 42. The communication openings 74 are respectively formed. The first communication opening 72 has an inner diameter that is substantially the same as or slightly larger than the through hole 56, while the second communication opening 74 has a larger diameter than the orifice hole 58 by a predetermined dimension. ing.

The spacer plate 70 has a plurality of long rectangular windows 76 formed therein. And
The spacer plate 70 is arranged such that the first communication opening 72 and the second communication opening 74 provided in the connection plate 68 are opened with respect to the respective windows 76. It is superimposed on the connection plate 68.

Further, on the surface of the spacer plate 70 opposite to the side on which the connection plate 68 is superposed, a closing plate 66 is superposed. Is covered. As a result, a pressurizing chamber 46 communicated with the outside through the first and second communication openings 72 and 74 is formed inside the ceramic base 44.

Incidentally, such a ceramic substrate 4
Numeral 4 is formed as an integrally fired product of ceramics. That is, as a specific manufacturing process, first, a green sheet is formed from a ceramic slurry prepared from a ceramic raw material, a binder, a solvent, and the like using a general apparatus such as a doctor blade apparatus or a reverse roll coater apparatus. I do. Then, if necessary, the green sheet is subjected to processing such as cutting, cutting, and punching, so that the window 76 and the first and second communication openings 7 are formed.
2, 74, etc., to form precursors for each plate 66, 68, 70. Then, by laminating and firing each of these precursors, an integrated ceramic substrate 44 is obtained.

The material of the ceramic forming the ceramic base 44 is not particularly limited, but alumina, zirconia, or the like may be used from the viewpoint of moldability.
It is preferably adopted. The plate thickness of the closing plate 66 is preferably 50 μm or less, more preferably 3 to 12 μm.
The thickness of the connection plate 68 is preferably at least 10 μm, more preferably at least 50 μm, and the thickness of the spacer plate 70 is preferably at least 50 μm, more preferably at least 100 μm.

That is, since the ceramic base body 44 formed as described above is formed as an integrally fired product of ceramics, it is not necessary to add a special bonding process or the like. On each superposed surface of the connection plate 68 and the spacer plate 70, complete sealing can be stably obtained.

In addition, in the ceramic substrate 44,
The presence of the connection plate 68 also provides an effect of improving manufacturability. That is, in general, a laminated body obtained by laminating thin green sheets having flexibility is difficult to handle.For example, in setting to a firing furnace, etc., distortion is added if the supporting method is not careful, damage or breakage occurs after firing. There is a problem that abnormal deformation easily occurs. However, in the laminate in which the connection plate 68 exists, the rigidity of the laminate is increased, so that the connection plate 6
8 becomes easier to handle than when it does not exist,
The occurrence of defective products due to handling mistakes can be suppressed. Further, in the case of a design in which the pressure chambers 46 are densely arranged in the ceramic base 44, the closing plate 66
In addition, even when handling is almost impossible with the structure including only the spacer plate 70, the presence of the connection plate 68 has an advantage that handling becomes possible.

Although the shape of the ceramic base 44 slightly varies depending on the manufacturing method, the shape of the ink nozzle member 42 is not limited.
It is desirable that the bonding surface of the connection plate 68, that is, the outer surface of the connection plate 68 is flat. As the degree of flatness, the maximum undulation with respect to a reference length of 8 mm is 50 μm or less, preferably 25 μm or less, when undulation is measured by a contact type shape measuring instrument.
More preferably, the thickness is 10 μm or less. Further, as one of means for achieving the flatness, it is possible to subject the ceramic base body 44 after integrally firing to mechanical processing such as polishing or plane cutting.

Further, in the ceramic base 44, the piezoelectric / electrostrictive elements 78 are respectively provided on the outer surface of the closing plate 66 at the portions corresponding to the respective pressurizing chambers 46.
Are provided. Here, the piezoelectric / electrostrictive element 78 is formed by forming a piezoelectric / electrostrictive operating portion including a lower electrode 77, a piezoelectric / electrostrictive layer 79, and an upper electrode 75 on a closing plate 66 by a film forming method. It was formed. And particularly preferably, the piezoelectric /
As the electrostrictive element 78, the applicant of the present application has previously described in Japanese Patent Application No. Hei.
The piezoelectric / electrostrictive element proposed in Japanese Patent Application No. 203831 and Japanese Patent Application No. 4-94742 is adopted.

More specifically, when obtaining the piezoelectric / electrostrictive element 78, the closing plate 66 is mainly composed of zirconium oxide whose crystal phase is partially or completely stabilized by a predetermined compound. A ceramic substrate is preferably used. Note that "partially stabilized or completely stabilized zirconium oxide" means that when heat or stress is applied, the crystal transformation does not occur partially or at all.
It contains zirconium oxide in which the crystal layer is partially or completely stabilized.

Compounds which stabilize the zirconium oxide include yttrium oxide, cerium oxide, magnesium oxide and calcium oxide. Zirconium will be partially or completely stabilized. Furthermore,
The content of each compound is 2 mol% to 7 mol% for yttrium oxide, 6 mol% to 15 mol% for cerium oxide, and 5 mol% to 12 mol% for magnesium oxide and calcium oxide. Among them, it is particularly preferable to use yttrium oxide as a partial stabilizer, in which case 2 mol% to 7 mol%, more preferably 2 mol% to 2 mol%.
Desirably, it is 4 mol%. Zirconium oxide obtained by adding and containing yttrium oxide in such a range has a main crystal phase partially stabilized in a tetragonal crystal or a mixed crystal mainly composed of a cubic crystal and a tetragonal crystal, and provides excellent substrate characteristics. Become. In addition, in order for the tetragonal crystal to be stably present and to obtain a large substrate strength, the average crystal grain size of the substrate is also important. That is, the average particle diameter is preferably 0.05 μm to 2 μm, more preferably 1 μm or less.

On the outer surface of the closing plate 66, predetermined electrode films (upper and lower electrodes) 75 and 77 and a piezoelectric / electrostrictive layer 79 are formed by various known film forming methods such as screen printing and spraying. Thick film forming techniques such as, dipping, coating, ion beam, sputtering, vacuum deposition,
It is formed by a thin film forming technique such as ion plating, CVD, and plating. The film formation can be performed before or after the sintering of the closing plate 66 (the ceramic substrate 44). The respective films (electrode films 75, 77 and piezoelectric / electrostrictive layer 79) thus formed on the closing plate 66 are subjected to heat treatment as needed. Each time each film is formed,
It may be performed simultaneously, or may be performed simultaneously after all the films are formed. Further, in order to improve the insulation reliability between the electrode films 75 and 77, if necessary,
An insulating resin film may be formed between the electrostrictive layers 79,79.

The material of the electrode films 75 and 77 constituting the piezoelectric / electrostrictive operating portion is not particularly limited as long as it is a conductor that can withstand a high-temperature oxidizing atmosphere at about the heat treatment temperature and the firing temperature. For example, a simple metal or an alloy may be used, and a mixture of an insulating ceramic or glass with a metal or an alloy, or a conductive ceramic may be used.
However, preferably, an electrode material mainly containing a high melting point noble metal such as platinum, palladium, and rhodium, or an alloy such as silver-palladium, silver-platinum, and platinum-palladium is suitably used.

Further, the piezoelectric / electrostrictive operating portion constituting
As the material of the electrostrictive layer 79, any material may be used as long as it exhibits an electric field-induced strain such as a piezoelectric or electrostrictive effect. It may be a crystalline material, a semiconductor material,
A dielectric ceramic material or a ferroelectric ceramic material may be used without any problem, and may be a material that requires a polarization treatment or a material that does not require it.

However, the piezoelectric / electrostrictive material used in the present invention is preferably a lead zirconate titanate (PZT).
) -Based material, lead magnesium niobate (P
MN-based material, lead nickel niobate (P
NN-based material, lead manganese niobate-based material, lead antimony stannate-based material, zinc zinc niobate-based material, lead titanate-based material And further, a composite material of these materials and the like are used. In addition, lanthanum,
Materials containing oxides such as barium, niobium, zinc, cerium, cadmium, chromium, cobalt, strontium, antimony, iron, yttrium, tantalum, tungsten, nickel, manganese and other compounds as additives, for example, There is no problem even if the above-mentioned predetermined additive is appropriately added to the above-mentioned material containing PZT as a main component so as to become PLZT.

The electrode film 7 formed as described above
5, 77 and a piezoelectric / electrostrictive film (layer) 79 generally have a thickness of 100 μm or less, and the electrode films 75, 77 generally have a thickness of 2 μm or less.
The thickness of the piezoelectric / electrostrictive film 79 is preferably not more than 50 μm, more preferably not less than 3 μm and not more than 40 μm in order to obtain a large displacement at a low operating voltage. It is desirable that:

That is, in the piezoelectric / electrostrictive element 78 thus formed, the closing plate 66 made of a material containing zirconium oxide as a main component and having a crystal phase partially stabilized is used as a substrate. Therefore, mechanical strength and toughness can be advantageously ensured even at a thin plate thickness, a large displacement can be obtained at a relatively low operating voltage, and a fast response speed and a large generating force can be obtained. You can.

In addition, since the piezoelectric / electrostrictive elements 78 are formed by a film forming method, due to the advantage of the film forming process, a large number of the piezoelectric / electrostrictive elements 78 are formed on the closing plate 66 at a fine interval with an adhesive or the like. Therefore, as described above, it is possible to form a plurality of piezoelectric / electrodes with respect to the portions respectively corresponding to the plurality of pressure chambers 46 formed in the ceramic base 44 as described above. Electrostrictive element 78
Can be formed easily and with excellent mass productivity.

Thus, the ceramic substrate 4 as described above
In the piezoelectric / electrostrictive actuator 45 in which the piezoelectric / electrostrictive element 78 is integrally provided on the ink nozzle member 42, as shown in FIG. Then, they are joined and integrated using an appropriate adhesive, for example, an epoxy resin or the like.
Thereby, based on the operation of the piezoelectric / electrostrictive element 78 of the actuator 45, the ink guided through the ink supply channel 62 is supplied to the pressurizing chamber 46 from the orifice hole 58, and the ink is supplied to the through hole. Thus, the target ink jet print head 40 ejected to the outside through the nozzle holes 54 through 56 and 57 is formed.

Incidentally, as described above, the actuator 4
When the ink nozzle member 42 and the ink nozzle member 42 are bonded to each other, the communication between the pressurizing chamber 46 provided in the actuator 45 and the ink supply channel 62 and the nozzle hole 54 provided in the ink nozzle member 42 constitutes the actuator 45. The first communication opening 72 and the second communication opening 74 formed in the connecting plate 68 are connected to the through holes 56 and the orifice holes 58 formed in the orifice plate 50 constituting the ink nozzle member 42. It will be done by letting them communicate.

Therefore, if the sealing property of the ink flow path between the bonding surfaces of the actuator 45 and the ink nozzle member 42 is ensured only around the first and second communication openings 72 and 74. Since the length of the bonding portion for which the sealing property should be ensured is short, excellent sealing property can be obtained advantageously and stably. Further, since it is possible to advantageously prevent the adhesive from protruding into the pressurizing chamber 46 and the occurrence of a gap in the bonding surface, it is possible to stably obtain a product having improved ink ejection characteristics. is there.

In this embodiment, the inner diameters of the first and second communication openings 72 and 74 are determined by the inner width of the pressure chamber 46 (the window 76 formed in the spacer plate 70).
Of the first and second communication openings 7 formed adjacent to each other.
The dimension between 2, 74 (L in FIG. 2) can also advantageously be ensured.

[0039] Thereby, the bonding area between the actuator 45 and the ink nozzle member 42 around each of the first and second communication openings 72 and 74 can be advantageously and sufficiently secured. Even in the case of bonding between different kinds of materials, it is possible to more advantageously obtain the sealing property on the bonding surface.

Depending on the type and application method of the adhesive, there is a possibility that the adhesive protrudes into the first and second communication openings 72 and 74 and closes the openings. If there is such a danger, the inner diameters of the first and second communication openings 72 and 74 formed adjacent to each other are set to the pressure chamber 4.
It is desirable to set the same size as the inside size of 6 so as to prevent the opening from being closed. As shown in FIG. 7, one or both of the first and second communication openings 72 and 74 may be formed in a teardrop shape or an elliptical shape.

Incidentally, the excellent sealing property of the ink flow path as described above, which is exerted on the joint surface between the ink nozzle member 42 and the actuator 45 in the ink jet print head 40 of this embodiment, is shown in FIGS. The ink nozzle member 16 and the actuator 2 required in the ink jet print head of the conventional structure shown in FIG.
It can be easily understood by comparing the shape of the bonding surface with No. 5 with that of the above embodiment.

Although the embodiment of the present invention has been described in detail, this is a literal example, and the present invention is not construed as being limited to such a specific example.

For example, the piezoelectric / electrostrictive actuator of the present invention can be used as an ink pump for an ink jet print head having various structures in addition to the above-described structures, as well as a micro pump, a piezoelectric speaker, a sensor, a vibrator, It can also be used as an oscillator, a filter, and the like.

Further, the structure of the piezoelectric / electrostrictive actuator is not limited to the above-mentioned embodiment.
For example, in the above-described embodiment, the ink supply channel 62 that supplies ink to the pressurizing chamber 46 is formed inside the ink nozzle member 42, but the ink supply channel 62 is formed inside the actuator 45. It is also possible.
One specific example is shown in FIG. In FIG. 4, to facilitate understanding, members and portions corresponding to those in the first embodiment are denoted by the same reference numerals. .
The orifice hole 58 in the specific example of FIG.
The function of the orifice hole 58 is integrated with the second communication opening 74 of FIG. 1 etc. by appropriately selecting the hole diameter of the second communication opening 74 in the example of FIG. is there.

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, various changes, modifications, improvements and the like can be implemented in an embodiment,
It goes without saying that all such embodiments are included within the scope of the present invention, without departing from the spirit of the present invention.

[0046]

As is clear from the above description, in the piezoelectric / electrostrictive actuator having the structure according to the present invention, the piezoelectric / electrostrictive element is easily formed with excellent mass productivity by the film forming method. Therefore, improvement in product quality and productivity can be achieved, and downsizing can be advantageously achieved. Further, since the ceramic base has a three-layer structure of a closing plate, a spacer plate, and a connection plate, such an actuator has sufficient rigidity even in a state of a green sheet laminate before firing, and is easy to handle. It has the feature of being excellent in manufacturability.

Further, since the ceramic base has a three-layer structure of a closing plate, a spacer plate, and a connection plate, the piezoelectric / electrostrictive actuator can be used as an ink pump of an ink jet print head, for example, to form an ink nozzle. When adhering to another member such as a member, the sealing property of the ink flow path at the joint surface between the actuator and the ink nozzle member can be dramatically improved, thereby improving the product quality and stabilizing it. Can be achieved advantageously.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view showing an example of an ink jet print head using a piezoelectric / electrostrictive actuator according to the present invention.

FIG. 2 is an explanatory sectional view taken along the line II-II in FIG.

FIG. 3 is an exploded perspective view illustrating a structure of the inkjet print head illustrated in FIG. 1;

FIG. 4 is an explanatory longitudinal sectional view corresponding to FIG. 1, showing an ink jet print head using a piezoelectric / electrostrictive actuator as another embodiment of the present invention.

FIG. 5 is an explanatory longitudinal sectional view showing a specific example of a conventional ink jet print head.

FIG. 6 is a sectional view taken along the line VI-VI in FIG. 5;

FIG. 7 is an explanatory sectional view showing an example in which the shapes of first and second communication openings are changed in FIG. 2;

[Brief description of reference numerals]

 40, 80 Ink jet print head 42 Ink nozzle member 44 Ceramic base 45 Actuator 46 Pressurizing chamber 48 Nozzle plate 50 Orifice plate 52 Flow path plate 54 Nozzle hole 58 Orifice hole 62 Ink supply flow path 66 Closing plate 68 Connection plate 70 Spacer plate 72 First communication opening 74 Second communication opening 78 Piezoelectric / electrostrictive element

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) H02N 2/00 H01L 41/18 101C 101D (72) Inventor Nobuo Takahashi 2 Toei Park Heights 305

Claims (1)

[Claims] 1. A piezoelectric / electrostrictive actuator in which a part of a wall of a pressurizing chamber formed inside a base is deformed by a piezoelectric / electrostrictive element to generate a pressure in the pressurizing chamber. A spacer plate provided with at least one window, a closing plate that is overlaid on one side of the spacer plate and covers the window, and a window that is overlaid on the other side of the spacer plate. A connection plate having an opening at a position corresponding to the window to be covered is laminated with a green sheet, and the base is constituted by a ceramic body which is integrally fired. Composed of electrodes and piezoelectric / electrostrictive layers formed on the outer surface of the
A piezoelectric / electrostrictive actuator, wherein the piezoelectric / electrostrictive element is constituted by an electrostrictive operation section.